<center> # Quantification of Behaviour in Neuroscience ### Jennet Baumbach ### September 15th 2023 <img src = "data:image/png;base64,#https://media2.giphy.com/media/eljCVpMrhepUSgZaVP/giphy.gif?cid=ecf05e479cxcoknwf2gzak1xi7wujabofvq75kddc7hh3dse&ep=v1_gifs_search&rid=giphy.gif&ct=g",width="400", height="400"/> --- ## The Importance of Behaviour to Neuroscience -- ### **Behaviour**: The activity of an organism interacting with its environment. -- - Naturalistic behavioural patterns are not synonymous with stimulus responses. -- - In laboratory settings, we primarilly study stimulus responses. -- ### **Monistic** view point: behaviour is the summated output of the underlying neural processes. -- - Alterations in behavioural output represents changes in the underlying neuronal processes --- # Historical Perspective -- ### The mind-body problem (aka monism vs. dualism) -- - **Dualism**: the idea that the mind and body are separate (distinct) entities -- - Aristotle (300 BCE), Plato (400 BCE), Rene Decartes (1600's) -- - Rationalized that the body and the "soul" or the "mind" were clearly distinct -- + the death of the body is separate from the existence of the soul --- # Historical Perspective -- ### Early neuroscience (1800's - 1950's) relied heavilly on behaviour. -- Clinical case studies: e.g. [Phineas Gage (1848)](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7735047/#:~:text=Gage's%20case%20is%20considered%20to,personality%2C%20emotions%20and%20social%20interaction.&text=Prior%20to%20this%20case%2C%20the,and%20unrelated%20to%20human%20behavior.) -- .pull-left[ <img src="data:image/png;base64,#https://upload.wikimedia.org/wikipedia/commons/2/28/Phineas_gage_-_1868_skull_diagram.jpg",width="350", height="300"/> ] -- .pull-right[ <img src="data:image/png;base64,#https://upload.wikimedia.org/wikipedia/commons/thumb/1/1b/Phineas_Gage_Cased_Daguerreotype_WilgusPhoto2008-12-19_EnhancedRetouched_Color.jpg/600px-Phineas_Gage_Cased_Daguerreotype_WilgusPhoto2008-12-19_EnhancedRetouched_Color.jpg",width="350", height="300"/> ] -- **Post-injury behavioural patterns** provided support for cerebral localization and information about the role of the damaged brain region (PFC). --- # Historical Perspective -- - The dualist perspective was challenged by increasing support for the connection between brain and mind during the 1800's -- + Rather than dualism being "disproven", science adopted the monistic viewpoint because of the volume of evidence to support it. -- - [Paul Broca (1861)](https://en.wikipedia.org/wiki/Paul_Broca) linked behavioural defects in clinical populations with brain lesion (identified during post-morterm analysis) -- + Indicated that there was localization of specific cognitive function distributed across the cortex. -- <center> <img src = "https://i0.wp.com/biomedguide.com/wp-content/uploads/2019/10/Broca_Wernicke.jpg?fit=487%2C301&ssl=1"> --- # Historical Perspective -- ### 1900's-recently, focus shifted towards molecular approaches.E.g.: -- .pull-left[ <img src = "data:image/png;base64,#https://neurosciencenews.com/files/2022/06/learning-memory-mechanism-neuroscience.jpg" height = "250", width="400"/> ] -- .pull-right[ - A complex behaviour (here, freezing behaviour) is reduced to a mechanisms represented at the level of a single neuron. - Has provided many pieces of insight about the molecular processes that contribute to to complex behaviour - Fundmentally lacks qualitative information about *how* these processes produce the behaviour in the context of the system. ] --- # Historical Perspective -- ### Recent renewed interest in the study of behaviour -- - Behaviuoral work can aim to *understand* in ways that neural interventions cannot. + Complex behavioural characterization should precede the formation of neural hypotheses. -- - Criticism of approaches that involve inference of cognitive processes from neural processes (e.g. [mirror neurons: Caslie et al. 2011](https://www.semanticscholar.org/paper/The-Mirror-Neuron-System-Casile-Caggiano/a3357d5d183cdd47ecbe352f34d7aec7e37fd8a0)) -- + And clear separation of results versus interpretations. -- .footnote[[Neuroscience needs behaviour: correcting a Reductionist Bias (Krakauer et al., 2017)](https://www.cell.com/action/showPdf?pii=S0896-6273%2816%2931040-6)] --- # The Connection between Brain & Behaviour -- <center> <img src="data:image/png;base64,#https://d3i71xaburhd42.cloudfront.net/a3357d5d183cdd47ecbe352f34d7aec7e37fd8a0/23-Figure5-1.png",width="333",height="200"/> </center> The **result** is that similar patterns of neural firing were observed when the individual performs the behaviour, or, when the individual watches another perform that same behaviour. The **interpretation** has been that the patterns of firing represent some levels of "understanding". --- # Historical Perspective -- ### Recent renewed interest in the study of behaviour -- - Technological developments improve the speed and accuracy in collecting behavioural data. -- - Producing more complex datasets -- - Which facilitate more comprehensive analytic approaches --- ## Animal Behaviour as a Readout for Brain Function -- ### Lesion studies -- - A loss of a specific behaviour after a specific brain region allows researchers to infer the functionality of the brain region. -- <center> <img src="data:image/png;base64,#lesions.png" width="50%" /> </center> .footnote[[Hutcheson et al. 2022](https://link.springer.com/article/10.1007/s002130000635)] --- ## Animal Behaviour as a Readout for Brain Function ### Lesion studies - A loss of a specific behaviour after a specific brain region allows researchers to infer the functionality of the brain region. -- .pull-left[ <img src="data:image/png;base64,#latency.png" width="815" /> ] -- .pull-right[ <img src="data:image/png;base64,#H_intake.png" width="827" /> ] -- <center> <b>The lesion approach does not inform about <i>how</i> the brain region contributes to the behaviour</b>. </center> .footnote[[Hutcheson et al. 2022](https://link.springer.com/article/10.1007/s002130000635)] --- ## Animal Behaviour as a Readout for Brain Function -- ### Developmental perspective -- - Changes in behavioural output across the lifespan suggest alterations in brain maturation. -- <center> <img src = "data:image/png;base64,#https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4730600/bin/13041_2016_191_Fig3_HTML.jpg"/> </center> .footnote[[Shoji et al. 2016](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4730600/)] --- # Behavioural Paradigms in Research -- ### The importance of well-defined behavioural tests -- #### Reliability (*does the measure produce consistent results*) -- - test-retest reliability (within or between individuals) -- - inter-rater reliability -- #### Validity (*are you really quantifying what you think you're measuring?*) -- - face validity - Does it "check out"? -- - pharmacological validity - Do pharmaceutical agenst that are known to regulate the processes that the measure is assumed to capture alter the behaviour in the expected ways? + e.g. administration of an anti-anxiety drug should increase anxiolytic behaviour.. -- - translational validity --- # Behavioural Paradigms in Research -- ### Example: Tasks to investigate memory in the lab -- Non-aversive memory measures -- - Operate on the basis that animals have a **preference for novelty** -- + Robust cross-species examples of this preference -- <center> <img src = "data:image/png;base64,#https://histogene.co/wp-content/uploads/2020/12/PMC4280055_medscimonit-20-2733-g002.png"/> --- # Behavioural Paradigms in Research -- ### Example: Tasks to investigate memory in the lab -- Aversive memory measures -- - Operate on the basis that animals fear pain -- + Robust cross-species examples of this behaviour -- <center> <img src = "data:image/png;base64,#https://www.e-phy-science.com/wp-content/uploads/sites/3690/2022/06/eps-fear-conditioning.png",width="400", height="300"/> --- ## Tapestry Analogy -- - Courtesy of [Prof. Dawn Good](https://brocku.ca/social-sciences/psychology/people/dawn-good/) -- .pull-left[ <img src="data:image/png;base64,#https://previews.123rf.com/images/niknikpo/niknikpo1503/niknikpo150300010/38075069-colorful-gobelin-tapestry-texture-close-up-background.jpg",height="250",width="250"/> ] -- .pull-right[ <img src="data:image/png;base64,#https://www.metmuseum.org/-/media/images/blogs/now-at-the-met/2014/making-a-tapestry/boreas-and-orithyia.jpg",height="250",width="250"/> ] --- ## Challenges and Limitations -- ### Variability in animal behaviour -- - Both between and within individuals -- ### Complex Nature of Animal Behavior -- - Contextual considerations: generally animals are tested one at a time in novel behavioural contexts. -- - Natural complexities: very difficult to confidently identify playing versus aggressive behaviour -- ### Animal Origens -- - Selective breeding for desireable lab characteristics has unknown influences on animals' behavioural output. --- # Hierarchical Framework of Scientific Thought -- ### **Theory**: A unifying scientific concept that is supported by many individual pieces of evidence. -- - Examples: Evolution, relativity, synaptic plasticity in neuroscience. -- - Individual scientists do not generally interact directly with theories on a day-to-day basis -- + e.g. no grant proposal aims to tackle a theory. -- - Acts as the conceptual starting point for researchers. --- # Hierarchical Framework of Scientific Thought -- ### **Model**: deals with one chunk of a scientific theory -- #### (1) Unifying models -- Are large, and typically fairly crystallized. -- - e.g. the genetic basis of inheritance, epigenetics, LTP in neuroscience. + Provide mechanistic insight into the overarching theory of evolution. -- #### (2) Working models -- Which are typically smaller in scope and often more flexible. -- - A unifying model could encompass many working models -- - e.g. Epigenetics: DNA methylation, histone modifications. Neuroscience: changes in dendritic shape / density . --- # Hierarchical Framework of Scientific Thought -- ### **Hypothesis**: isolates one experimentally-testable aspect of a a working model. -- - Facilitates the formation of *testable predictions* that are usually directional in nature. -- - A hypothesis can never be "proven correct" - it can only be "not disproven" -- - A hypothesis gains support through repeated testing of its predictions. -- - The wording of the hypothesis should lend itself well to discussion and rigorous experimental design. -- - "Hypothesis driven" writing is the gold standard for research reports, grant applications and thesis projects. -- - e.g. in LTP, could form a hypothesis: synaptic strengthening facilitates long-term memory via the NMDA receptor --- # Hierarchical Framework of Scientific Thought -- ### **Experiment**: An emperically designed series of steps designed to investigate the predictions that arise from the hypothesis. -- - Involves some kind of control group. -- - Either quasi-experimental or true experimental design. -- + quasi- examples: Males versus females, clinical populations versus healthy control group. -- - Differentiation from "study" in psychology. --- # Hierarchical Framework of Scientific Thought -- ### **Measure** or **Assay**: A specific endpoint that will produce interpretable data. -- - e.g. a specific behavioural task or laboratory assay. --- # Styles of Experiments -- #### 1. Observe: An initial observed association between two things (e.g. A, C) initiates the research design process. -- Design hypothesis: A -> B -> C -- #### 2. Measure: Confirm that A causes B -- #### 3. Block: inhibiting B should prevent A from causing C -- Design an experiment to prevent B while leaving the processes that cause A and C intact (necessity) -- #### 4. Mimic: experimentally manipulating B should prdoduce C -- Design an experiment to alter B to investigate whether this will produces C in the absence of A (sufficieny) -- .footnote[[David Sweatt - Mechanisms of memory textbook ](https://www-sciencedirect-com.myaccess.library.utoronto.ca/science/article/pii/B9780123749512000044?via%3Dihub)] --- ## Future Directions in animal behavioural research -- #### Improvements in the quantification of behavioural data provide richer, more complex datasets. -- - Much more efficient (e.g. eliminiates the need to sit scoring videos for many hours) -- - Can use an exhaustive approach combined with unbiased clustering methods. -- .pull-left[  ] -- .pull-right[  ] --- ## Future Directions in animal behavioural research -- ### Improvements in the complexity of statistical analysis allow for richer interpretatins about behavioural patterns -- - e.g. Time-series based analyses (a concept borrowed from finance) -- <center> <img src = "data:image/png;base64,#https://cdn.corporatefinanceinstitute.com/assets/Time-Series-Analysis-1024x729.png",width="350", height="350"/> --- <center> # Questions ? :) --- <img src="data:image/png;base64,#Week_2_slideshow_Behaviour_files/figure-html/unnamed-chunk-4-1.png" width="65%" style="display: block; margin: auto;" />